This invention relates to a separable hinge assembly for automotive vehicle folding seats and more particularly to an improved separable hinge assembly for a removable folding seat cushion incorporating a fail-safe installation feature.
The U.S. Pat. No. 4,888,854 issued Dec. 26, 1989 to Russell et al., assigned to the assignee of the present application, entitled a Folding Seat Hinge Assembly With Quick Disconnect enables a folding seat cushion to be readily removed and reinstalled in a vehicle.
The separable seat hinge assembly disclosed in the Russell, et al. '854 patent comprises a body mounting or body-half hinge plate and a seat cushion mounting or seat-half hinge plate. The body mounting plate is formed with a channel-shaped cross-section having a base portion fixed to a rearwardly sloped footwall section of the vehicle floor pan. Side webs extend from the body-half plate base portion and have mirror image generally V-shaped slots with each slot including an angled open-end slot portion and an angled blind-end slot portion.
The patented Russell, et al. dog-leg shaped seat-half hinge plate, generally indicated at 30' in prior art FIG. 4A of the drawings, includes a planar tongue portion 64' and a cantilevered neck portion 66'. The tongue portion 64' is formed with crimped sides 68' and rivets 72' secure the tongue portion to the seat cushion 22' undersurface hardened back 38'. The neck portion 66' is formed with a U-shaped cross-section defining a bight section having parallel side flanges 74'. The side flanges 74' terminate at their lower free ends in a pair of parallel ears 76' fixedly supporting a transverse pintle pin 36 therebetween. Formed on the ears 76' are mirror image outboard directed dual locking cam sectors 78' and 80'. Each cam sector is disposed in an imaginary arc of a circle, having its center on the pintle pin axis, and comprises an intermediate chordal portion 90' terminating at its free ends in first and second sets of tangent cam shoulders 78a' and 80a' defining a substantially ninety degree central angle of the arc. A forward wing portion 96 projects laterally from each side of the body-half plate 32' providing a planer camming surface adapted for engagement by its associated seat-half first and second cam shoulders.
As shown and described in the '854 Russell patent with the seat cushion located in its normal mode each seat-half plate pintle pin 36' is captured in the blind-end slot portions of its associated body-half plate such that the first set of cam shoulders are in flush frictional engagement with their associated wing camming surface. Upon the seat cushion being rotated forward about the pintle pins to its overcenter folded mode each first set of cam shoulders are unlocked and each second pair of cam shoulders are pivoted into flush frictional engagement with their associated wing camming surface.
To remove the seat cushion it is only necessary to pull a side loop on the cushion to release a locking latch and pivot the seat cushion forward from its normal in-use seating mode to an intermediate upright release position adapted for lift-off removal. After swinging the seat cushion to its intermediate release position about the pintle pins each hinge assembly seat-half plate first and second sets of cam shoulders are located in spaced relation to their associated body-half plate camming surfaces. The operator then urges the upright seat cushion rearwardly causing the pintle pins to be moved out of their blind-end slot portions into their upwardly directed open-end slot portions. The operator next lifts the upright seat cushion vertically, freeing the seat-half hinge plates from their associated body-half hinge plates, and enabling ready removal of the seat cushion from the vehicle.